Process for enhancing the stability to water of effects produced mechanically on textiles containing cellulose



Patented Dec. 21, 1937 PROCESS FOR. ENHANCING THE STABILITY TO WATER OF EFFECTS PRODUCED ME- CHANICALLY ON TEXTILES CONTAINING CELLULOSE Andreas Ruperti, Basel, Switzerland, assignmto Society of Chemicallndustry in Basle, Basel,

Switzerland No Drawing. Application March 23, 1936, Serial 8 Claims.

It is known practice to produce mechanically on textiles containing cellulose efiects such as are obtainable, for example, by the action of pressure, if desired in cognation with heat, as

5 is the case in the treatment with an embossing .calender. Such effects, howeved, are only stable so long as they do not come into contact with water. If the impressed textile is washed or exposed to rain or to a moist atmosphere, the effect is more or less completely lost.

This invention relates to a process by which the resistance of these effects to the action of water may be increased in a surprising manner by conversion of the cellulose into a cellulose 15 derivative which in comparison with the original cellulose has a diminished capacity for swelling in water, in the sense that not only a moist atmosphere or rain, but also hot washing, dyeing and like treatments, have a diminished-tendency to injure the effect. In this manner results are obtained which hitherto could not be achieved except in a complicated manner during weaving. The effects in, question may be produced by any known process, for example by stamping,

25 pressing, ironingor the like.

As parent materials there may be used 'textiles which consist of or contain native cellulose 01 any origin, whether pretreated or not, for instance cotton, mercerlzed cotton, ramie, flax, hemp or the like,- or of regenerated cellulose,

for instance viscose, cuprammonia cellulose, denitrated cellulose, cellulose obtained by precipitation of solutions of cellulose in quaternary ammonium salts, and native and regenerated cellulose, or cellulose, native or regenerated, and

other fibers. .The parent materials most important are piece-goods or knitted goods; for

certain purposes loose material'or thread may" be used. The parent material may be undyed 40 or may have been previously dyed with a dyestufl stable to-the treatment. v

For converting the cellulose into thecellulose ester which, in comparison with the original cellulose, as described above, has a diminished 5 capacityior swelling in water, there may be used any known esterifying agents and methods which esterify cellulose with retention of the structure. These methods are well known and some of these are for example described in the specifica- In Switzerland March 28, 1935 (on. s-2oi brace as a part of the operation a treatment having a swelling effect on cellulose, for example, a treatment in aqueous solution, the desired effects must be produced after this part Of the operation. d

The esterification can be carried out in a suitable apparatus with the aid of a suitable acylating agent, for example an acid anhydride, such as acetic anhydride, propionic anhydride, butyric .anhydride, valerianic anhydride, isovalerianic anhydride, monochloracetic anhydride, phthalic anhydride, or with an acid chloride; such as acetyl, chloride, propionyl chloride, butyryl chloride, palmityl chloride, stearoyl chloride, benzoyl chloride, in presence or absence of an alkaline catalyst, such as sodium acetate, potassium acetate, potassium carbonate or potassium sulfite, orof a neutral or acid catalyst, such as sulfuricacid, zinc chloride, copper sulfate; and in presence or absence of a solvent or diluent, such as benzene, benzine, xylene,, chlorobenzene, perchlorethylene, pyridine, with or without preliminary swelling of the material, for instance with a base, an acid or a concentrated solution of salt; or with a suitable etherifying agent, such as benzyl chloride; in either case the treatment must not destroy the structure of the parent .material.

When piece-goods are under treatment, the

process is advantageously conducted as a continuous operation.

The cellulose constituents of the material pro- I duced differ in their behaviour in thematter of Viscose satin or crepe satin piece-goods are impregnated with a solution of potassium acetate of per cent strength, dried, pressed on an embossing calender with a fancy pattern and treated for half-an-hour at 90 C. with a solution of 5 per cent of acetic anhydride in benzine.

'The esterifying liquid is sucked oil, or simply drained off, whereupon the acetylated material 50 is dried with recovery of the volatile constituents of the treating liquor which still adhere to it. It is then washed with water and dyed with an acetate silk dyestuff in a manner usual for dyeing acetate silk. The embossed eflect remains through all these operations and is completely stable to water and washing. In like manner a durable imitation crepe may be produced by embossing an artificial silk fabric impregnated with potassium acetate and subsequently acetylated.

Example 2 Cotton piece-goods are passed through an embossing calender and treated for 3 hours at 50 C. with 15 times their weight. of a solution of 30 per cent strength of acetic anhydride in glacial acetic acid in presence of zinc chloride amounting to 1 per cent by weight of the solution. After separating the adhering acetylating liquor the goods are washed with water and dried. The embossed efiect remains, even when the goods are subsequently dyed or washed.

Example 3 Cotton piece-goods are folded and pressed hot so that a pleating effect is produced. The goods are then treated with 10 to 15 times their weight of a solution of 10 per cent strength of benzoyl chloride in pyridine for half-an-hour at 80 C., and then washed with water and dried. A pleating eilect stable to water is produced.

What I claim is:-

l. A process for enhancing the stability to water of efiects unstable to water produced locally by 3. A process for enhancing the stability to water of eflects unstable to water produced locally by mechanical means on textiles containing cellulose, which consists in esterifylng the cellulose, alter the eifect has been produced, with an aliphatic acid anhydride in the presence of a potassium salt of a weak aliphatic acid.

' 4. A process for enhancing the stability to water of eiiects unstable to water produced locally by mechanical means on textiles containing cellulose, which consists in esterifying the cellulose, after the effect has been produced, with acetic anhydride in the presence of potassium acetate.

5. A process for enhancing the stability to water of eflects unstable to water produced locally by mechanical means on cotton, which consists in esterifying the cotton, after the effect has been produced, with an aliphatic acid anhydride in the presence of a potassium salt of a weak aliphatic acid.

6. Aprocess for enhancing the stability to water of efiects unstable to water produced locally by mechanically means on cotton, which consists in esterifying the cotton, after the effect has been produced, with acetic anhydride in the presence of potassium acetate.

7. A process for enhanc ng the stability to water of effects unstable to water produced locally by mechanical means on regenerated cellulose, which consists in esterifying the regenerated cellulose, after the effect has been produced, with an aliphatic acid anhydride in the presence 01' a potassium salt of a weak aliphatic acid.

8. A process for enhancing the stability to water of efiects unstable to water produced locally by mechanical means on regenerated cellulose, which consists in esterifying the regenerated cellulose,

after the eiiect has been produced, with acetic anhydride in the presence of potassium acetate.

ANDREAS RUPERTI. 

